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Vol.47, No.8, 461 ~ 466, 2009
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| Title |
| Molecular Dynamics Simulations of the Diffusion of Bimetallic Nanoclusters Supported on Graphite |
| 박준우 Joon Woo Park , 이주성 Ju Seong Lee , 민찬호 Chan Ho Min , 이현석 Hyun Seok Lee , 류지훈 Ji Hoon Ryu , 서동화 Dong Hwa Seo , 이혁모 Hyuck Mo Lee |
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| Abstract |
| We study the diffusion of Ag based bimetallic nanoclusters supported on graphite. Using a molecular dynamics simulation, we reveal that the Ag clusters show rapid diffusion because of their hexagonal bottom layer. In order to decrease the rate of diffusion, we added Pt and Ni to distort the structure of the alloy cluster (i.e., the alloying method). We expected Pt to provide a stronger force on Ag atoms, and Ni to shorten the bond length and thereby change the structure of Ag cluster. However, the attempt was unsuccessful, because Pt and Ni atoms formed cores inside the Ag clusters. We therefore designed a collision system where large Ag clusters collide with small Pt or Ni clusters. Upon collision with Pt clusters, the diffusion showed little change, because Pt atoms are substituted at the Ag atomic site and form a perfectly ordered structure. The collision with Ni, however, deforms the bottom layer as well as the overall cluster structure and decreases diffusion. This outcome appoints toward the possibility of further application to the manufacture of durable nanocatalysts. |
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| Key Words |
| nanocluster, molecular dynamics simulation, diffusion, bimetal, alloy, collision |
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